PRS04
Masses in Potentials
Consider 3 equal masses sitting in
different gravitational potentials:
A) Constant, zero potential
B) Constant, non-zero potential
C) Linear potential (V ∝ x) but
sitting at V = 0
Which statement is true?
1.
2.
3.
4.
None of the masses will accelerate
Only B will accelerate
Only C will accelerate
All masses will accelerate, but B
will have the largest acceleration
5. All masses will accelerate, but C
will have the largest acceleration
PRS04
Positive Charge
Place a positive charge in an electric
field. It will move from
1. higher to lower electric potential;
lower to higher potential energy
2. higher to lower electric potential;
higher to lower potential energy
3. lower to higher electric potential;
lower to higher potential energy
4. lower to higher electric potential;
higher to lower potential energy
PRS04
Negative Charge
Place a negative charge in an
electric field. It will move from
1. higher to lower electric potential;
lower to higher potential energy
2. higher to lower electric potential;
higher to lower potential energy
3. lower to higher electric potential;
lower to higher potential energy
4. lower to higher electric potential;
higher to lower potential energy
PRS04
Potential and Energy
Which is true?
I. It takes positive work to bring
like charges together.
II. Electric field lines always point
in the direction of decreasing
electric potential.
III. If a negative charge moves in
the direction of the electric field,
its potential energy decreases.
1. II only.
2. II and III only.
3. I, II and III.
4. I and II only.
5. I only.
PRS04
Two Point Charges
The work done in moving a positive
test charge from infinity to the point
P midway between two charges of
magnitude +q and –q:
+q
P
-q
1. is positive.
2. is negative.
3. is zero.
4. can not be determined since not
enough information is given.
5. I don’t know
PRS04
Potential Landscape
If I think of the electric potential as
a mountain range, then the electric
field points:
1) Up the mountain sides
2) Down the mountain sides
3) Around the mountain sides
4) I don’t know